Precompute sign

Please refer to the Session creation section to learn how to create a new session.

Full example

ECDSA

App.tsx

import { EcdsaSession } from '@silencelaboratories/silent-shard-sdk';

const messageHash = 'e2a159d17b7bb714aed7675d7c7d394dec8d2e4337842848104694bf89c71c03';

export const preSign = async (session: EcdsaSession) => {
  // Creating a new keyshare for demo purpose. In real application, you can use an existing keyshare.
  const keyshare = await session.keygen();

  const signConfig = {
    keyshare,
  };
  const preSignature = await session.preSign(signConfig);

  console.log('Pre computed signature:', preSignature);

  // The signature is a base64 encoded string.
  const preSignConfig = {
    preSignB64: preSignature,
    messageHash,
  };
  const signature = await session.finishPresign(preSignConfig);

  console.log('Final Signature:', signature);
};

EdDSA

App.tsx

import { EddsaSession } from '@silencelaboratories/silent-shard-sdk';

const messageHash = 'e2a159d17b7bb714aed7675d7c7d394dec8d2e4337842848104694bf89c71c03';

export const preSign = async (session: EddsaSession) => {
  // Creating a new keyshare for demo purpose. In real application, you can use an existing keyshare.
  const keyshare = await session.keygen();

  const signConfig = {
    keyshare,
  };
  const preSignature = await session.preSign(signConfig);

  console.log('Pre computed signature:', preSignature);

  const preSignConfig = {
    preSignB64: preSignature,
    messageHash,
  };
  const signature = await session.finishPresign(preSignConfig);

  console.log('Final Signature:', signature);
};

• The preSign method takes a EcdsaPreSignConfig(EdDsaPreSignConfig) object as an argument.

  • keyshare is the client's "share" of the MPC wallet.

• The preSignature is the precomputed signature(Base64 string) of the message to be signed.

• The finishPresign method takes a EcdsaFinishPreSignConfig(EdDsaFinishPreSignConfig) object as an argument.

  • preSignB64 is the precomputed signature from the preSign method.
  • messageHash is the hash of the message to be signed as a hex string.

• The signature is the ECDSA(EdDSA) signature (hex string) of messageHash, corresponding to the public key (or address) of the wallet.